So here recently my keyboard has been locking up terribly bad. Respringing, rebooting, restarting will not fix it. I uninstalled bitesms and CK still was acting up. Then i uninstalled mobile substrate, that did the trick but i was wondering what would have caused this so i can stear clear from that tweak, FOREVER!!! lol. I had just recently jailbroke it with jailbreakme 3.0 if that helps any as well.

I don't think it's safe to not have mobilesubstrate. If your device crashes for whatever reason (say...an app fails or Cydia tweak is incompatible) you won't be able to recover from it and you'll have to restore. Mobilesubstrate protects your phone from that, that's why Safe Mode occurs after a crash on the Springboard, because of mobilesubstrate. You should consider reinstalling it. The problem I really doubt is within it but within something else you installed with Cydia. It could also just be the jb didn't go right, so a redo might be in order.

I don't think it's safe to not have mobilesubstrate. If your device crashes for whatever reason (say...an app fails or Cydia tweak is incompatible) you won't be able to recover from it and you'll have to restore. Mobilesubstrate protects your phone from that, that's why Safe Mode occurs after a crash on the Springboard, because of mobilesubstrate. You should consider reinstalling it. The problem I really doubt is within it but within something else you installed with Cydia. It could also just be the jb didn't go right, so a redo might be in order.

OTOH,
there are a myriad of addons and hacks that ride on top of MobileSubstrate,
many of which actually CAN make your phone less stable, and cause any and all kinds of grief and misery.

The original poster may not be far off-
however the fix in these cases is to disable the mobilesubstrate addons and hacks, not mobilesubstrate itself.

If you want to use a jailbroken phone, and are not a gonzo like geohot or saurik,
you're far far far far far better off running mobilesubstrate than not. And ripping it out of a running jailbroken system could result in "bad things" happening, yes.